Wearable portable ultrasound probe with dual array and system

ABSTRACT

Disclosed are wearable ultrasound probes for use in trauma triage and assessment. The probes define a finger-receiving aperture and include an ultrasound array disposed adjacent the distal end wherein the ultrasound array is angled toward the bottom side of the probe about 10-50 degrees from the longitudinal axis and a second ultrasound array adjacent the distal end and proximal to the first ultrasound array, wherein the second ultrasound array is angled about 105-155 degrees from the first ultrasound array.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Applications62/634,132 entitled Wearable Ultrasound Probe and System, and62/634,101, entitled Graphical User Interface for Ultrasound System,both of which are hereby incorporated by reference in their entiretiesfor all purposes. It is a continuation-in-part of U.S. Nonprovisionalpatent application Ser. No. 16/272,146, entitled Wearable UltrasoundProbe and system, and Ser. No. 16/272,181 entitled Graphical UserInterface for Ultrasound System, which are incorporated herein byreference in their entireties for all purposes.

STATEMENT OF GOVERNMENT SUPPORT

This invention was made with government support under contract numberW81XWH-17-C-0024 awarded by The United States Army Medical Research andMaterial Command, and W81XWH-15-C-001 awarded by the Defense HealthProgram, United States Department of Defense. The government has certainrights in the invention.

TECHNICAL FIELD

Embodiments relate to medical imaging technologies, and morespecifically, to portable ultrasound technologies

BACKGROUND

Many trauma patients have injuries that are not apparent on the initialphysical examination. For example, patients with penetrating cardiactrauma, blunt or penetrating abdominal trauma, or chest trauma may havesustained life threatening injuries without much external blood loss.Without rapid assessment of internal bleeding, these injuries may beoverlooked in the initial assessment of a patient, and appropriatetreatment may be delayed.

Ultrasound imaging can be used to identify the accumulation ofintraperitoneal or pericardial free fluid and/or collapsed lung intrauma patients. Emergency physicians in the United States began usingbedside or Point of Care (POC) ultrasound imaging of trauma patients inthe 1980's. Ultrasound imaging has since become the initial imaging testof choice for trauma care in the United States and is part of theAdvanced Trauma Life Support protocol developed by the American Collegeof Surgeons.

POC ultrasound imaging of trauma patients consists of either the FocusedAssessment using Sonography in Trauma (FAST) exam or the extended FASTexam (eFAST).

Ultrasonic eFAST examination provides a universally-accepted triage andtrauma assessment tool. The eFAST exam is quicker and less expensivecompared to computative tomogrpahy (CT) imaging, and thus can providevital information without the time delay caused by radiographs or CTimaging. An experienced user can conduct an eFAST examination in fiveminutes.

An eFAST examination involves seven to nine separate scans. Each scanrequires the operator to move the probe to a different area of the body,adjust the operation of the probe, and acquire and interpret scans ofthe relevant physiology. Some scans should be performed with an entirelydifferent probe. The eFAST exam typically requires two probes: one witha low frequency ultrasound array, i.e., 1-5 MHZ, for deep abdominalscans, and a probe with a high frequency ultrasound array, i.e., 5-13MHZ, for shallow scans, such as to detect pneumothorax or collapsedlung. Low frequency phased arrays have the additional advantage of beingable to minimize visual interference from ribs, and high frequencyarrays provide greater image clarity for near field viewing as describedfurther below. For many portable or cart-based ultrasound systems, anoperator must disconnect one probe, connect another probe, adjust thesystem to accommodate the change in probe, position the probe at therelevant area of the body, and acquire and interpret the image. Themajority of hand-held ultrasound systems requires two different probesto conduct an eFAST examination—one of each high and low frequency.

The number of scans and sequence in which eFAST scans are performed issubject to the personal preference of the clinician performing the scan,informed by the clinical impression of the patient. A clinician whosuspects collapses lung or pneumothorax will likely begin theexamination with thoracic scans, while a clinician who suspectsabdominal trauma may begin the examination in the pelvic region.

Battlefield medics have an urgent need for a fast and effective way totriage individuals who have sustained traumatic injuries. The eFAST examwould provide battlefield medics with an important triage tool. However,battlefield medics are typically inexperienced or novice ultrasoundoperators. Conventional equipment is designed for the use of operatorswith extensive experience and training in the use of ultrasound. Itprovides little structure or guidance in order to afford the operatorwith the opportunity to conduct the test in accordance with his or herpreferences and impressions of the patient as informed by clinicaljudgment. This lack of structure or guidance does not provide aninexperienced operator with necessary support. Novice users and eventhose who use ultrasound infrequently typically find conventionalcontrols and/or user interfaces to be counterintuitive and unhelpful.This lack of structure or guidance is not a problem in the context of aclinic or hospital, where personnel having specialized training andexperience operating ultrasound systems are readily available. Butbattlefield medics must triage patients with the skills they have, oftenunder exceptionally stressful circumstances.

Bulky equipment cannot be carried into the field without compromisingthe mobility and safety of the operator. Switching back and forthbetween probes and adjusting the machine accordingly make additionaldemands on a medic who is fully occupied with triaging and caring forpatients.

Emergency responders who are not battlefield medics also must accuratelyand rapidly triage patients under extraordinarily demanding anddifficult circumstances including but limited to mass shootings, naturaldisasters, etc. eFast examinations would also be of value to emergencyresponders, but many of the same problems with conventional systems maketheir use by emergency responders in the field impractical.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a lateral sectional view of an ultrasound probe that can beoptionally worn on a finger, illustrating the angle between thelongitudinal axis and the first array, in accordance with variousembodiments;

FIG. 2 is a lateral sectional view of the ultrasound probe of FIG. 1,illustrating the angle b′ between the longitudinal axis and the axis bof the second array, in accordance with various embodiments;

FIG. 3 is a lateral sectional view of the ultrasound probe of FIG. 1,illustrating the angle c′ between the axis a of the first array and theaxis b of the second array, in accordance with various embodiments;

FIG. 4 illustrates the angle of the ultrasound probe of FIG. 1 when thesecond array is being used, in accordance with various embodiments;

FIG. 5 is a lateral sectional view of one embodiment of a dual-arrayultrasound probe as disclosed herein, illustrating the angle e′ betweenthe axis f of the the first array and the axis g of the second array, inaccordance with various embodiments;

FIG. 6 is a lateral sectional view of the ultrasound probe of FIG. 5,illustrating the angle h′ between the longitudinal axis and the axis gof the second array, in accordance with various embodiments;

FIG. 7 is a perspective view of another example of a wearable ultrasoundprobe, in accordance with various embodiments;

FIG. 8-8A includes two rear perspective views of two embodiments of awearable ultrasound probe, showing two different versions offinger-receiving apertures and finger-retaining elements, in accordancewith various embodiments;

FIG. 9-9A includes cross-sectional views of the two finger-receivingapertures and finger-retaining elements of FIG. 8, in accordance withvarious embodiments;

FIG. 10 illustrates one example of a graphical user interface forconducting an eFAST examination;

FIG. 11 illustrates one example of a graphical user interface forconducting an eFAST examination.

FIG. 12 illustrates a series of five probe embodiments in which theplacement of arrays were varied for testing; in accordance with variousembodiments; and

FIG. 13A-13C includes three perspective views of an ultrasound system inaccordance with the various embodiments disclosed herein in which theprocessing component is removably affixed to the display as discussedherein.

FIG. 14 illustrates an ultrasound system in accordance with the variousembodiments disclosed herein in which the processing component isintegral with the display.

FIG. 15 illustrates an ultrasound system in accordance with the variousembodiments disclosed herein wherein the processing component is affixedto the back of the display, and both are mounted to the chest of bodyarmor.

FIG. 16 illustrates an ultrasound system in accordance with the variousembodiments disclosed herein wherein the processing component anddisplay are affixed to a component of the patient's bed.

FIG. 17 illustrates an ultrasound system in accordance with the variousembodiments disclosed herein wherein the processing component anddisplay are affixed to a wall.

FIG. 18 illustrates the use of ultrasound systems in accordance with thevarious embodiments disclosed herein wherein the display is held inusers' hands.

FIG. 19 illustrates an ultrasound system in accordance with the variousembodiments disclosed herein wherein the processing component anddisplay are affixed to body armor.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which are shownby way of illustration embodiments that may be practiced. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope. Therefore,the following detailed description is not to be taken in a limitingsense, and the scope of embodiments is defined by the appended claimsand their equivalents.

Various operations may be described as multiple discrete operations inturn, in a manner that may be helpful in understanding embodiments;however, the order of description should not be construed to imply thatthese operations are order dependent.

The description may use perspective-based descriptions such as up/down,back/front, and top/bottom. Such descriptions are merely used tofacilitate the discussion and are not intended to restrict theapplication of disclosed embodiments.

The terms “coupled” and “connected,” along with their derivatives, maybe used. It should be understood that these terms are not intended assynonyms for each other. Rather, in particular embodiments, “connected”may be used to indicate that two or more elements are in direct physicalor electrical contact with each other. “Coupled” may mean that two ormore elements are in direct physical or electrical contact. However,“coupled” may also mean that two or more elements are not in directcontact with each other, but yet still cooperate or interact with eachother.

For the purposes of the description, a phrase in the form “A/B” or inthe form “A and/or B” means (A), (B), or (A and B). For the purposes ofthe description, a phrase in the form “at least one of A, B, and C”means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).For the purposes of the description, a phrase in the form “(A)B” means(B) or (AB) that is, A is an optional element.

The description may use the terms “embodiment” or “embodiments,” whichmay each refer to one or more of the same or different embodiments.Furthermore, the terms “comprising,” “including,” “having,” and thelike, as used with respect to embodiments, are synonymous.

Embodiments herein provide wearable, finger-mounted ultrasound probesand small, portable ultrasound systems that may be used for diagnosingtrauma, for example using the eFAST examination. Conventional ultrasoundsystems include two components: a probe and a workstation. The probecontains the array or arrays of ultrasound transducer elements thatconvert electrical impulses to ultrasonic energy and vice-versa. Eitherthe probe or the workstation includes front end functions, such as beamforming or creation of electrical impulses which are converted to andfrom ultrasonic energy by the array. The workstation contains acomputational back-end, which processes the image data generated by thefront end, a display, and a user interface including a keyboard or othermeans of input of user control.

These components are typically fairly large, which makes them unsuitablefor use in the field and difficult to move from area to area within afield hospital, aid station, or other emergency medical setting. Evenportable systems typically are no less than laptop computer-sized, whichis still prohibitively large for field environments, where minimizingthe gear a medic or responder must carry is critical. Additionally,emergency medical technicians, search and rescue professionals, andmedics who must operate in conditions impacted by combat or naturaldisasters have urgent needs for medical imaging in order to betterassess the nature and extent of injuries, but conventional ultrasoundtechnology is too complex or difficult to carry and deploy quickly.

Additionally, in a traditional clinical setting, multiple personneltypically are available to perform different roles, including caringfor, stabilizing, and treating the patient and performing diagnosticactivities including operating an ultrasound system, obtaining images,and interpreting those images. In such a setting, personnel aregenerally available who have received extensive training and/or haveextensive experience with ultrasound, and ultrasound examinations aregenerally conducted by such individuals. And because other personnel areavailable to perform other roles, ultrasound operators are able to focuson performing ultrasound examinations.

In contrast, a first responder or military field medic must examine,support, triage, and stabilize patients in a potentially challengingenvironment. They do not generally have the opportunity to developextensive expertise, training, and experience in operating an ultrasoundsystem, obtaining images, or understanding and interpreting ultrasoundimages. Nor do they generally have the ability to focus exclusively onthe conduct of an ultrasound examination, as other tasks as well as thechallenges of their settings compete for their attention.

In order to be useable in an emergency setting outside of a conventionalhospital, a system must be compact enough to be easily transported, andit must be as simple and intuitive to use as possible in order tominimize demands on the user's attention and cognitive capacity, yet itmust provide sufficient support to enable a user with a relative lack ofspecialized skills to effectively and efficiently conduct theexamination.

To address these issues, the disclosed systems may include an ultrasoundprobe that emits and receives ultrasonic energy, and a portablecomponent that is electrically connected with the ultrasound probe toprovide power and ultrasound beamforming technology to the ultrasoundprobe, and to a tablet, mobile phone, or other small wireless computingdevice. These components may be interconnected by USB cable or othermeans. In various embodiments, the disclosed systems also may include atleast one user interface, such as a GUI, that may be displayed on atablet, mobile phone, or other small wireless computing device, and atleast one set of instructions stored on and executable by the tablet,phone, portable component, or other small wireless computing device. Inuse, execution of the instructions by the tablet, mobile phone, or othersmall wireless computing device may cause the portable component and inturn the ultrasound probe to emit and receive ultrasonic energy inaccordance with one or more sets of preset parameters, and the userinterface may allow a user to select one of the sets of presetparameters to carry out one or more steps of the eFAST exam. In variousembodiments, the mobile phone and/or tablet may include some processingrequirements that the beamformer and/or portable component cannotperform. In those embodiments, some processing of the data transmittedfrom the portable component may be performed by software on the tabletand or mobile phone.

In various embodiments, the portable systems may communicate through aUSB cable, standard wireless or limited, ultra-wide-band wireless (UWB)to a tablet, phone, or other portable wireless device, which functionsas the display and user interface. In various embodiments, the probesmay include a first array that includes a low frequency phased array,and a second array that includes a high frequency linear array. In otherembodiments, the probes include only the high frequency linear array. Invarious embodiments, the disclosed systems and probes may allow a fieldmedic or other operator to use a single, compact probe to carry out allof the steps of an eFAST exam, which may reduce the amount of equipmentthat must be carried with or by the operator. Additionally, the systemmay include a tablet- or mobile phone-based graphical user interface(GUI) that may direct a user with little training in ultrasonography tocarry out an eFAST exam effectively in a battlefield environment.

In various embodiments, the array or arrays are positioned on the probein such a way as to maximize ergonomics for the user. If the probe hasmore than one array, the arrays are positioned with respect to oneanother in an orientation that minimizes the change in hand positionrequired to switch between arrays, while also providing sufficientseparation between the first and second arrays to make it easy for aninexperienced user to track which array is being used (and consequently,to be able to easily interpret the resulting ultrasound images).Disclosed herein are probes having arrays positioned with respect to oneanother at angles that satisfy these conditions. In other embodiments,the probe contains a single array which is oriented with respect to thehousing to maximize user ergonomics. Such probes may be wearable andintended to mount on a finger, having receptacles for the accommodationof a user's finger. However, these angles are also applicable to probesthat are not worn or finger-mounted, especially small, lightweighthand-held probes.

FIG. 1 is a lateral sectional view of an ultrasound probe, illustratingthe angle between the longitudinal axis and the first array, inaccordance with various embodiments. As illustrated, the probe 100 mayinclude a housing 102 having a top side (as illustrated in FIG. 1) and abottom side (as illustrated in FIG. 1), a proximal end (right, asillustrated in FIG. 1) and a distal end (left, as illustrated in FIG.1), and a longitudinal axis extending therebetween and generallyaligning with the longitudinal axis of the operator's finger when in use(labeled 0-180 in FIG. 1). For the purpose of this disclosure, thelongitudinal axis is measured along the bottom edge of the strain relief110, which rests on the dorsal surface of the user's finger during usein a finger-mounted probe.

The proximal end of the housing (closest to the operator in use) mayoptionally include a finger-receiving aperture 108 so that the housingmay be slid onto a user's finger. If the probe has two arrays, the firstultrasound array 104 may be disposed at the distal end of the housing,near the user's fingertip. The axis of the first array 104 isillustrated by line a in FIG. 1. As illustrated in FIG. 1, in variousembodiments, the angle a′ between the longitudinal axis and the axis aof the first array 104 may be about 60-105 degrees, such as about 65-100degrees, about 70-95 degrees, about 75-90 degrees, about 80-85 degrees,or about 83-84 degrees relative to the longitudinal axis.

FIG. 2 is a lateral sectional view of the finger-mounted ultrasoundprobe of FIG. 1, illustrating the angle b′ between the longitudinal axisand the axis b of the high frequency linear array 106, in accordancewith various embodiments. As illustrated in FIG. 2, the high frequencylinear array 106 may be disposed near the distal end of the housing 102.In various embodiments, the angle b′ between the longitudinal axis andthe axis b of the high frequency linear array 106 may be about 10-50degrees, such as about 15-45 degrees, about 20-40 degrees, about 20-30degrees, or about 24-25 degrees relative to the longitudinal axis.

FIG. 3 is a lateral sectional view of the finger-mounted ultrasoundprobe of FIG. 1, illustrating the angle c′ between the axis a of thefirst array 104 and the axis b of the second array 106, in accordancewith various embodiments. As illustrated in FIG. 3, in variousembodiments, the angle c′ between the axis a of the first array 104 andthe axis b of the second array 106 may be about 105-155 degrees, such asabout 110-145 degrees, about 115-135 degrees, about 115-125 degrees, orabout 120 degrees.

Where two arrays are present, the separation between the first array andthe second array needs to be large enough for the user to easilydistinguish between the two arrays during use, but the hand angle alsoneeds to be comfortable during use so as not to cause strain on the handand wrist of the user. The angles and ranges defined above define aunique set of values that meet both of these conflicting needs. Invarious embodiments, the first and second arrays may be orientedparallel to each other. In some embodiments, both the first and secondarrays may be transverse relative to the longitudinal axis.

FIG. 5 is a lateral sectional view of a dual-array probe in accordancewith various embodiments, illustrating the angle e′ between the axis fof the first array 104 a and the axis g of the second array 106 a, inaccordance with various embodiments. As illustrated in FIG. 5, invarious embodiments, the angle e′ between the axis f of the first array104 a and the axis f of the second array 106 a may be about 105-155degrees, such as about 110-145 degrees, about 115-135 degrees, about115-125 degrees, or about 120 degrees.

FIG. 6 is a lateral sectional view of an ultrasound probe in accordancewith various embodiments illustrating the angle h′ between thelongitudinal axis and the axis g of the high frequency linear array 106a, in accordance with various embodiments. In various embodiments, theangle h′ between the longitudinal axis and the axis g of the highfrequency linear array 106 a may be about 10-50 degrees, such as about15-45 degrees, about 20-40 degrees, about 20-30 degrees, or about 24-25degrees relative to the longitudinal axis. In accordance with certainembodiments, the linear array 106 or 106 a needs to lie flat on thepatient for performing scans such as the pneumothorax portion of theeFAST exam, as well as for other applications like line placements.However, if the angle h′ is too shallow the user's ability to applyappropriate pressure with the probe may be compromised. In theseembodiments, the angle between the longitudinal axis and the axis of thearray may be about 10-50 degrees, such as about 15-40 degrees, about20-30 degrees, or about 24 degrees relative to the longitudinal axis.

In general, probes of various shapes and architectures permit varyingfields of views. For example, a curved linear array with relativelysmall radius of curvature permits imaging in the near field of the probeover a wide field of view. A phased array permits imaging over a widefield of view at some distance from the array, while allowing imagingthrough a narrow access. A linear array permits imaging over a narrowerfield of view, but provides good imaging of structures near the surfaceof the array.

The presently disclosed dual-array probes include a phased array as thefirst array 104 or 104 a which is positioned at the distal end of thehousing, and a linear array as the second array 106 or 106 a which ispositioned just proximal to the first array 104 or 104 a. Thisarchitecture allows an operator to carry out the bulk of the eFAST examusing the first array, which is positioned at the tip of the probe andangled slightly toward the bottom surface (e.g., angled slightly towardthe pad of the finger tip when the probe is worn) to optimize ease ofuse and to afford an intuitive, ergonomic hand position during theexamination. The second array, which is located adjacent to the firstarray, may be accessed by the operator with a slight change in handangle for the pneumothorax-detection portions of the eFAST exam. Theangle between the first and second arrays is optimized so that arelatively untrained operator may easily switch between arrays withoutconfusion, while still maintaining an ergonomic hand position.

The two arrays may be oriented so that they have the same scan plane,which is preferably transverse to the user's finger. Having both arraysoriented in the same scan plane means that changing the array does notchange the scan plane, which makes switching between arrays moreintuitive for novice or inexperienced users. If the user desires to ascan plane that is transverse to the user's finger, he or she can usethe array located at the tip of the finger, and can rotate his or herfinger to rotate the array, a movement which is intuitive.Alternatively, he or she can hold the probe in his or her hand androtate it.

In various embodiments, the first and second arrays are oriented in atransverse direction, which permits a user to begin the examination withhis or her hand transverse to the length of the patient's torso, whichis a more natural position than parallel to the length of the patient'storso. Additionally, the combination of a straight linear array and aphased array allows the probe head profile to be minimized.

In various embodiments, the disclosed probes are particularlyadvantageous for use by field medics who lack specialized ultrasoundexpertise because the ergonomic form of the probe leverages innatehand-eye coordination to simplify use and training. The paralleltransverse orientation of the two arrays helps prevent confusion in aninexperienced user, which is particularly important in high-stresssettings, such as the battlefield. Additionally, the disclosed probeshelp keep a user's hand and arm available for other uses.

In various embodiments, the first and second arrays of the disclosedprobes may be electrically interconnected with a cable on a dorsalaspect of the probe. As illustrated in FIG. 1, a strain relief 110 maybe provided to house and protect the cable. The cable may be made offlex circuit or any other electrically conductive or connective materialthat may be employed to electrically couple to the first and secondarrays 104, 106.

FIG. 7 includes several views of the housing of the ultrasound probe ofFIGS. 1-4, all in accordance with various embodiments. FIG. 8 is twodistal perspective views of various embodiments of the probes disclosedherein. As shown, the probe 200 includes a first array (e.g., the phasedarray) 204 disposed at the distal end of a housing, and a second array(e.g., the linear array) 206 disposed adjacent the distal end, andproximal to the first array 204. The housing includes a headshell 207,strain relief 208, and nose piece 210. The housing positions the firstarray 204 and second array 206 in particular spatial relationships withrespect to the longitudinal axis and with respect to each other, asdescribed above. Each array includes of an array of ultrasound elements,such as piezoelectric elements or a CMUT sensor, which convertelectrical impulses into ultrasonic or acoustic energy and returningultrasonic energy into electrical impulses which can be processed intoimages.

In various embodiments, the housing may also include one or moreexternal gripping elements 410, for example that may be disposed on theleft and right sides of the housing, adjacent the distal end. Thesegripping elements may be a softer polymer surface, or they may be anarray of discrete elements formed from a softer polymer as dots orridges, or they may be textured areas. In use, when an operator insertsan index finger into the housing, the left and right external grippingmembers may be positioned where the thumb and middle fingers rest, sothat an operator may use the thumb and middle fingers to stabilize,rotate, and direct the probe in a desired direction/orientation toobtain a desired ultrasound image. Additionally, the external grippingelements may be used without inserting a finger into the probe, suchthat it may be used as a handheld probe when desired.

FIG. 9 includes cross-sectional views of the two finger-receivingapertures and finger-retaining elements of FIG. 8, in accordance withvarious embodiments. In various embodiments, the proximal end of thehousing, where the operator's finger is inserted, may include afinger-retention element 320 a, 320 b. In some embodiments, thefinger-retention element 320 a, 320 b may be formed from an elastomericand/or deformable material, such that insertion of the user's finger maycause at least a portion of the finger-retention element 320 a, 320 b toexpand or deform, thereby applying a gripping force to the finger. Invarious embodiments, the finger retention element may have a durometeror be made from a material having a durometer of about 30 A to 70 A,such as about 35 A to 65 A, or about 40 A to 60 A, or about 45 A to 55A,or about 50 A. By contrast, other portions of the probe housing may bemade of a harder material, such as ABS plastic, which may be about95-115 Shore D on the hardness scale.

More specifically, in various embodiments, the finger-receiving aperture308 a, 308 b may form a sleeve that includes a substantially tubularwall member formed from an elastomeric material. The sleeve may have aninner lumen sized to accommodate an average human index finger. In someembodiments, a portion of the substantially tubular wall may extend orproject into the lumen to form a deformable gripping member that gripsthe finger. The deformable gripping member may have any of severaldifferent cross-sectional forms, such as an inward curve, arc, crease,pleat, or fold, or a more complex shape such as a combination of curvesand/or folds that together form an “M” or “W” shape when viewed incross-section. In various embodiments, insertion of a finger into thesleeve may cause the inward-facing arcuate, creased, folded, or pleateddeformable gripping member to flex radially outward to accommodate thediameter of the finger. In so doing, the deformable gripping member mayexert a force against the finger surface that may help retain the probeon the finger during use. As illustrated in FIG. 9, an anthropometricrange of finger sizes may be accommodated by the finger-retentionelement 320 a, 320 b, from 5% (small circle 310) to 95-98% diameters(large circle 312). In various embodiments, the indented elastomericfinger-retention element 320 a, 320 b may distend to accommodate thelarge finger, yet grip the small finger. In various embodiments, the “W”shaped finger-retention element may accommodate a 95th percentile fingerdiameter, while the “M” shaped finger-retention element may accommodatea 98th percentile finger diameter.

As shown in FIG. 13, some embodiments of an ultrasound system inaccordance with the disclosure provided herein may include threecomponents: (1) the probe 402; (2) a processing component 400 which maycontain a multiplexor, user interface elements, ultrasound front endprocessing, a beamformer board, a battery, transducer interface board,wireless board, a heat pipe, and/or a blower fan; and (3) a tablet,mobile phone, or other wireless computing device 410 that includes backend processing capabilities and a touchscreen display, which acts as theprimary user interface. In various embodiments, the system may use a USBCable in lieu of a wireless connection.

A beamformer emits the electrical pulses which are transformed intoultrasonic energy by the probe and used to image the patient orsubstrate. The beamformer originates the signal, and times it in orderto focus the acoustic beam that emits from the array. The beamformerdetermines the amplitude and frequency of the signal. The beamformeralso receives the signal and demodulates, filters, detects, andcompresses the signal and converts ultrasound data into pixels, orprocessed image information which can then be converted to a videostream and fed to the display.

Synthetic beamforming may be used in some embodiments of the systemdisclosed herein. Synthetic beamforming generates ultrasound images byarchiving several transmit-receive events which are then coherentlysummed to form a synthetic beam. The inventors of the system describedherein have used synthetic beam forming to generate diagnostic qualityimages at up to 24 cm depth at 10 frames per second with a 32 channeltransmit and 16 channel receive stepped synthetic aperture.

In accordance with some embodiments of the system disclosed herein, theprocessing component may include may include ultrasound front endfunctionality, a transmit/receive switch, amplification, digitization,and beamformer, connection capability such as wi-fi, Ultra Wide Band, orUSB. Additionally, the processing component may store and executesinstructions supplied by the operating system that directs theperformance of the system.

The processing component 400 may alternatively be mounted beneath thedisplay, as shown in FIGS. 11a, 11b, and 11c , in which the processingcomponent is affixed in a bracket 408 which is removably affixed to atablet or mobile computing device 410 and positions the tablet or mobilecomputing device 410 where it can be seen by the operator.Alternatively, as shown in FIG. 12, the processing component may beaffixed to the back of the wireless computing device or other display410. The display and processing component may be affixed to stationarystructures such as a component of a cot, gurney, or bed, as shown inFIG. 16, or a wall, as shown in FIG. 17. It can also be held by anoperator as shown in FIG. 18. It may be clipped to the belt or clothingof a user (not shown). FIGS. 15 and 19 show the processing component anddisplay attached to the body armor of a user.

In various embodiments, the ultrasound systems disclosed herein may becontrolled by software that includes instructions to implement variousoperations recorded in non-transitory computer readable media. Theseinstructions may make up an operating system which directs the system toperform operations associated with system set up, system control,scanning, data acquisition, beamforming, signal processing, and imagecreation. The operating system may include data files and datastructures in addition to program instructions. The processors also mayinclude memory consisting of hardware specially configured to store andperform program instructions such as the operating system and to recordand store data and images generated by the system.

In various embodiments, the processing component also may include angraphical user interface, certain embodiments of which are shown inFIGS. 10 and 11, which receives signals generated by user interfaceelements on the tablet, mobile phone, or other computing device thatalters the action of the beamformer, processors, and/or other componentsin order to conform the performance of the system with the user input.For example, it may alter system performance in accordance with presetscanning parameters as described below.

Ultrasound scanning is subject to variable parameters, and manipulationof those parameters enables users to optimally image structures locatedat various depths within a substrate such as a patient's body.Ultrasound system user interfaces typically have some or all of thefollowing user inputs: a power switch, an ability to adjust the array,an ability to adjust the gain, or brightness or vividness of the signal,an ability to optimize images, and a zoom capability. In variousembodiments, a dual-array probe may be interconnected with a userinterface which enables a user to change the selected array. Batterychange indicators, screen brightness and contrast, and arrows to movebetween images are also important features. Finally, ultrasound systemuser interfaces typically allow users to freeze images and to save orrecord images or video.

Additionally, most ultrasound systems include presets, which are used toset standardized parameters for standardized scans. The extended,Focused Assessment using Sonography in Trauma (eFAST) exam is auniversally accepted triage and rapid assessment tool based on a rapidultrasound survey of key organs, internal bleeding, and heart and lungfunction. The FAST protocol involves serial scans: the subxiphoid fourchamber view and the parasternal long axis view of cardiac anatomy;abdominal and lower thoracic views including the upper peritoneum andMorison's pouch between the liver and right kidney and the lowerperitoneum posterior to the bladder in the male and the pouch of Douglas(posterior to the uterus) in the female; right coronal and intercostaloblique views in the mid-axillary line giving coronal views of theinterface between the liver and kidney; left coronal and intercostaloblique views from the posterior-axillary line producing coronal viewsof the spleen and diaphragm; longitudinal and transverse lower pelvicviews of the bladder (male/female) and uterus (female); and anteriorthoracic views of the pleural interface (to access pneumothorax) throughthe 3-4th intercostal space and midclavicular line.

An e-FAST examination is facilitated by preset parameters mostappropriate for each successive scan, e.g., gain, depth, scan plane, andother system parameters optimized for each area of the body scannedduring an eFAST exam, pre-programmed into the system and categorized byscan. A user can initiate an eFAST exam, causing the system toautomatically set system parameters optimized for the first scan inaccordance with the first pre-set. When a user has completed that scan,the user so indicates to the system, which saves the scan and thenchanges system parameters so that they are optimized for the next scanin accordance with the next pre-set, and so on.

Icons that represent each scan in an e-FAST exam permit a user toindicate which scan he or she would like to perform. In response to thatindication, the system is automatically configured to scan in accordancewith the preset parameters associated with that scan. Preset scanparameters mean that users need not adjust individual parameters whentransitioning between scans. Instead, users merely transition betweenpreset parameters as they transition between scans. Other presets may beused within the spirit and scope of the system disclosed herein. Forexample, presets may be defined by the area of the body to be imaged,for example, eye, breast, spleen, bladder, etc.

Examples: Evaluation of Probe Architectures

Five probe prototypes were developed to be evaluated for ergonomiccompatibility with the eFAST exam. These prototypes tested twovariables: (1) the angle from the surface of the patient toperpendicular to the patient (5.5 degrees to 52 degrees); and (2) theangle between the phased array and the linear array (105 degrees to 165degrees). All prototypes had the identical array scan plain orientations(phased array scan plane in parallel to the finger and the linear arrayscan plane perpendicular to the finger) and all had the phased arraynearest the tip of the finger. FIG. 12 illustrates a series of crosssectional views of five probe embodiments in which the placement of thefirst and second arrays were varied for testing; in accordance withvarious embodiments. More detailed illustrations of each design areshown in the Appendix.

A total of 13 emergency medicine residents (at Madigan Army MedicalCenter—MAMC) and 13 medical students (at College of Osteopathic Medicineof the Pacific Northwest—COMP) participated in the study. Separatetrails took place at each facility. A survey (identical for both sites)consisted of a questionnaire which the participants filled out afterusing both standard probes and mockups to perform a mock eFAST exam on amannequin dummy. Each eFAST exam view (5 total) was rated, plus anoverall rating was given for the standard probe and each mockup. Theresults from both sites are summarized in Tables 1 and 2.

Overall, Prototype C was rated the highest (average of 3.8) by both thestudents and residents and was most chosen by the residents whendirectly asked. Prototype C was also rated the best for time to completethe eFAST exam.

The cardiac (subxiphoid) view was rated overall the lowest for thefinger probes. Although the standard probe also had its lowest ratingfor the cardiac view, there appears to be a significant issue consistentacross all variants of the finger probe. Mockups C and D, with the arrayprimarily frontal, had the highest ratings among the mockups for thisview among the more experienced users.

Comparing the standard probe to the wearable probe is heavily dependentupon “familiarity.” The inexperienced user prefers the wearable formfactor because it is easy to use, intuitive, etc., while the experienceduser prefers the standard hand-held probe. The standard probe is veryfamiliar to the experienced user and thus does not present a problem tobe solved. The field medic will not be a trained user.

The most important attribute appears to be the angle of the phased arrayrelative to the finger plane (horizontal axis). In both C and D thearray was primarily “frontal” with an offset of only 15 degrees from theperpendicular face of the probe. The frontal aspect was important forallowing the probe to be placed with some pressure into the patient andalso allowed greater scanning freedom of movement.

The differentiation of the two arrays is important but appears to beless important than the frontal orientation of the phased array.Prototypes C & D had the angle between the arrays at 105 degrees and 152degrees, respectively (less angle indicates greater scan separation).Prototypes A, B & E were viewed as having insufficient angledifferentiations i.e. 165 degrees. Differentiation between arrays wasstated verbally to be important by several users as the speed in whichthe exam is conducted leaves no time for confusion (the user needs to“lock in” by tactile feel which array is being used).

The MAMC doctors indicated a preference that the scan planes point inthe same direction (relative to the finger) to make the probe moreintuitive and to reduce confusion of orientation when switching betweenarrays). This would also make the left and right upper quadrant viewsmore comfortable while standing adjacent to the patient. The statedpreference was to have both scan planes be perpendicular/transverse tothe finger.

While not intentionally studied, the small forward footprint of probe C(due to the large degree of separation between arrays and the frontalangle of the probe) was seen as an advantage. This made the probe seemfamiliar to experienced ultrasound users, a potential advantage, with noseeming disadvantage for less experienced users.

Given the similar ratings for C &D, it was interesting that C, perceivedthe best, was only 5.5 degrees; whereas, D was 52 degrees and receivedsimilar but slightly lower overall ratings. (However, this may be due toconfounding factors such as the small footprint and the identicalforward angle of both probes). In both variants, it is easy to push hardon the phased array because of the frontal orientation. The commentssuggest one design or the other; a compromise in the middle (i.e.Prototype E) may not be appropriate as noted and rated (i.e. 3.54) bythe Army doctors. (Given that C is a lower profile, it also has theadvantage for use with body armor and shock blankets.)

All finger probe variants had consistently low ratings for the cardiacview from both the students and doctors. The doctors' ratings wereparticularly low across the prototypes (i.e. 2.5 to 3.3). Alternativecardiac views such as the parasternal four-chamber view may be easier toobtain with the finger probe phased array.

There appears to be a clear advantage for Prototypes C & D for thePelvic and LUQ views. Also Prototype D is perceived as being very goodfor the pulmonary/pneumothorax view by the Army doctors (likely becauseof the greater finger angle relative to the linear array, offering amore comfortable hand position). The grips on each of the prototypeswere viewed positively. Participants even could tell that “E” had fewerraised dots due to its design. There is a positive aspect to the designwhen the clinician has permission to hold or use the finger inserted.

It can be seen that the frontal angle of the phased array relative tothe finger orientation is the same for both probes C and D. Since thearray angle separation varied significantly, yet both probes receivedsimilar scores, the array orientation may be less critical, at leastwhen separated beyond a critical angle. A final design will keep thefrontal orientation of the phased array relative to the finger angle andplace the linear scan angle somewhere between C and D versions. VersionD was rated higher for the pneumothorax view, the only eFAST scan thatuses the linear array. However D presents a larger footprint and lessarray separation, which detracted from the other views. As most eFASTexams are performed with the phased array, designs should be biasedtoward the C design, but slight angle increases of the linear probetoward the D design may improve comfort for the pneumothorax viewwithout detracting from the other views.

For example, the probes illustrated in FIGS. 1-8 represent intermediatesbetween probes C and D. One embodiment representing an optimization ofthese results is depicted in FIGS. 1-4. FIGS. 1-4 illustrate a preferredorientation of the first and second arrays, with the longitudinal axislabelled “0-180,” the angle of the first array relative to thelongitudinal axis labelled “a”, and the angle of the second arrayrelative to the longitudinal axis labelled “b”.

Although certain embodiments have been illustrated and described herein,it will be appreciated by those of ordinary skill in the art that a widevariety of alternate and/or equivalent embodiments or implementationscalculated to achieve the same purposes may be substituted for theembodiments shown and described without departing from the scope. Thosewith skill in the art will readily appreciate that embodiments may beimplemented in a very wide variety of ways. This application is intendedto cover any adaptations or variations of the embodiments discussedherein. Therefore, it is manifestly intended that embodiments be limitedonly by the claims and the equivalents thereof.

What is claimed is:
 1. A wearable ultrasound probe, comprising: ahousing having a top side and a bottom side, a proximal end and a distalend, and a longitudinal axis extending there between; wherein theproximal end comprises a finger-receiving aperture; a first ultrasoundarray disposed at the distal end; a second ultrasound array disposedadjacent the distal end and proximal to the first ultrasound array,wherein the second ultrasound array is angled about 105-155 degrees fromthe first ultrasound array; and wherein the first ultrasound array is aphased array and the second ultrasound array is a linear array.
 2. Thewearable ultrasound probe of claim 10, wherein the second ultrasoundarray is angled about 115-135 degrees from the first ultrasound array.3. The wearable ultrasound probe of claim 10, wherein the secondultrasound array is angled about 115-125 degrees from the firstultrasound array.
 4. The wearable ultrasound probe of claim 10, whereinthe first ultrasound array is angled about 60-105 degrees from thelongitudinal axis, and wherein the second ultrasound array is angledabout 10-50 degrees from the longitudinal axis.
 5. The wearableultrasound probe of claim 10, wherein the first and second arrays areoriented parallel to each other.
 6. The wearable ultrasound probe ofclaim 10, where the first and second arrays are oriented transverse tothe longitudinal axis.
 7. The wearable ultrasound probe of claim 10,wherein the finger-receiving aperture comprises a finger-retentionelement.
 8. The wearable ultrasound probe of claim 10, wherein thehousing further comprises a left side and a right side, and wherein theleft and right sides each comprises a gripping element.